Incubator heater



' G. E. CHRISTENSEN INCUBATOR HEATER Filed Aug. 1921 Gen/ e E C/vr/sfense/v INVENTOR.

BY 2 m i A TTORN g. 3

Patented Dec. 23, 1924.

UNITED STATES Gnomes n. CHRISTENSEN, or FULLERTON, NEBRASKA,

INCUBATOR HEATER,

Application filed August 30, 1921. Serial No. 496,838.

To all whom it may concern Be it known that I, GEORGE-E. (Imus/rensnN, acitizen of the United States, residing at Fullerton, in the county ofNance and State of Nebraska, have invented certain new and usefulImprovements in Incubator Heaters, of which the following isaspecification.

My invention relates to heating systems for hot-water incubators andmore particularly to the boiler unit of the heating systern. a boilerwith the minimum amount of labor and material, and which atthe same timehas the maximum efficiency in'responding to the rapid and suddenfluctuations in temperature'found in places where farm incubators areusually operated.

These and other objects will be more specifically referred to intheaccomp anying description, and in connection with the drawingsforming a part of this application, of which drawings,

Figure I shows the preferred form of my heater installed on anincubator, the incubator being shown diagrammatically and in outline,and with-partsbroken away to more clearly disclose-the boiler-and itsheat f boiler, and clearly diselosesthe inner partitioi'i'walls, as wellasthe proportion'o't the parts. i 1

In the figures". numeral 10 refers to the incubator itself. Theincubator is mounted on legs 'or'pegs 11 to-set it above the level ofthe floor or other supp'o "t. Access to the interior of theiincubatorisobtained by means of thedoor liarranged to swing on hinges All of thishowever is common to nearly all incubators, and is illustrated heremerely for the purpose oi showing 'how my heating system is applied 'tothe "incubator;

The boiler isindicated generally'by the reference llllnltl'al lit. Theboiler has two parallel side walls 15, an-end wall 16, and a partial topwalll't': I A vertical partition wall 18 extends dowi'iward'ly betweenthe parallel side wvalls from the inner extremity ot't-he top wall l'T.The lower end ofthe vertical wall 18 is connectedt-o the outer extremityof the top wall 17 by means of It chief object is the production of anupwardly and rearwardly inclined wall 19. The walls 17, 18, and 19 aresecured to the side walls 15 in water-tight relation, as for example bysoldering, but any other known method as welding, would accomplish thesame purpose. The result of this construction is a water containerhaving 'a flue positioned vertically at one end, and having an inclinedheating surface 19.

In the construction of the boiler, only two pieces of rectangular sheetmetal are used, and these pieces are" each bent at only two places. Theside walls 15- and the end wall 16 are formed by twice bending suchasheet of metal, as can readily be seen from an inspection of thedrawings. The top and partition walls are likewise formed from a singlesheet ot metal, which is cut toa predeteri'nined length andot' a' widthequal" to that of the end wallfand whe'nd'ient will form aright"triangularenclosure. In my preferredconstruction I make the walls1''? and 18' of approximately equal lengths, but the inclination of thewall 19 maybe varied by varying the'proportions of the lengths-oi: thewalls'17 and' l8. 511 1 a The water reservoir of the boiler is protitledwith a filling tube 21 in the uppcr wall "and preferablymear the upperend of the inclined wallp A cap or stopper 22 of any approved formcloses the mouth ot the filling tube to protect 't'hecontents of thereservoir "from: dust and other extraneous u'iatterwhich might interferewith the operation oi? the-heaterz On the side of the boiler mext totheineubator-a-re two apertures andQei; i-kperture nearthe t op*ot' thewater level iii-the ireservoir and preferably near tllfl'otlteliflld ofthe-inclined wall 19. Aperture 2%. is placed at or near the lowest pointor the" reservoir.

Pipesare connected with the; apertures to circulate thev water forheating) the incubator In the construction shown in Figure 1, pipe :isconnected to the reservoir at the aperture. 23 and serves to carry thehot water .irom the surface and into the egg chamber of the incubator.The pipe as shown=lies parallel to one of the sides of the incubate-rtand its end'is connected to pipe 26.which:is parallel to the side of theincubator opposit-ethe boiler. Thepipe :26 is in turn connected tothepipe 2,7 which is parallel to the third side of the incubator. Asshown, the three pipes 25, E26, and 27 he in asubstantially horizontalplane, but they may if desired, be given an inclination throughout. InFigure 1-the pipe 27 is; shown-connected to a pipe 28 which 1s parallelto the side of the incubator 21(112106111) to the boiler but inclineddownwardly to the level of the aperture 24:. I have shown the aperture24 as somewhat smaller in diameter than the aperture 23, and in theconstruction shown, the pipe 28 is reduced from the .di-

ameter of the larger aperture to the diameter'of the smaller aperture.The pipe 28 is connected to a short pipe 29 which passes out through thewall of the incubator and into the reservoir through the aperture 24c.

For heating the water a lamp 230 is positioned directly beneath the flueof the boiler. The lamp is mounted on an oil tank 31 from which it isfed, and the oil tank is filled through an opening which is normallykept closed by a cap 32. The lamp is provided with a chimney 33 whichhinges on the lamp base at 3 1-. The arrangement gives sufficientclearance for lowering the chimney when I it is desired to trim andclean the wick.

i of the thermostat constitutes a part of my invention, I do not desireto cumber thereoord with descriptions of old and well known structures.It will readily be seen however that when the shutter 35 is raised, theheated air from the lamp will passupward through the boiler flue withoutappreciably heating the'waterin the boiler, but when the shutterclosesthe outlet of the boiler flue, the heated air is deflected and passesunderneath" the heating wall 19 of the boiler. The-function of thethermostat is to raise or lower the shutter 35 as the temperature of theincubator gets above or below the normal.

*It is sometimes desirable to arrange all of thepipes of the heatingsystem to lie in one plane. "-In Figure 2 I have shown a modification ofthe boiler which permits of such an arrangement. In this constructionthe boiler itself is made exactly as before de-' y scribed, butthe'lower aperture serving to return the water to the boiler on itscircuit is enclosed in a box-like structure 38' extending' to or nearthetop of the boiler. box 38 is provided on its outer side with an aperture39 at or near the level of the aperture "It will readily be seen that inassembling the heating system, the return pipe can be made to approachthe boiler at the same level as that of the exit pipe, or if itis-desired to set the'entire piping system at a'slightincli'ne, theaperture 39 may be positioned slightly below the level of the aper- Theture 23. I have illustrated thebox structure 38 merely to show onemethod of connecting the piping system to the boiler, but it is apparentthat a number of other arrangements would also accomplish the samepurpose... For example, if the pipes 28 and 29 were kept in the plane ofthe pipes 25 and 26, another pipe could be jointed to and dropped fromthe end of the pipe 29 t0 the aperture 24, this extra length of pipebeing mounted perpendicularly and-between the boiler and the adjacentwall of the incubator. Still another way of doing this is to cut theaperture 24 at a higher level and to connect it with av downwardlyextending pipe on the interior of the boiler, the pipe being open at itslower end. In this case the return will be inside the boiler.

Asbefore said, the boilerv is of the simplest possible construction. Thesheet metal iscutinto two predetermined sizes, each rectangular in form.Each'piece is bent in only two places. The equipment for cutting thestrips,- for bending'them, for punching the holes, and for uniting thepieces in watertight relation is all found in every tin shop,

and the entire operation is so simple that it can be performedwith theminimum amount of unskilled labor.

\The heating surface 19 is inclined and is relativelylarge in size. Theheated air is held in contact with the heating surface 19 by the twowings of the sides 15 whichprevent lateral dissipation of the heated airand confines thecurrent to a narrow passage. This confined currentagainst the large heating surface 19 not only utilizes the maximumamountof'heat from the lamp but causes an almost instant response to the mostsensitive thermostat. This isforthe reasonthat when the flue 20 is fullyopen thesurface 19 becomes a positive cooling surface, being freely incontact with thecoo-ler air of the room.-. The surface 18 is in no sensea coolingsurface becauseit'is always in contact with more or less heatedair, nor does it serve as a heating surface because it is V8-l, ticaland thereby allows the heated air to pass over it without appreciablyaffecting its temperature. f The water heatersat present in use havehorizontal heating surfaces of small area, thus wasting a large amountof the heat,-and being more or less confined, these heating surfaces cannot function as cooling surfaces to vprevent the incubator fromoverheating:

I have had this heater in use on my incubator for twosuccessive seasons.I have constructed a number of them for trial purposes. I havefound thatthey are not only easily-"made and installed, but theyresult in apositive saving of fuel and of attention over all others'which I havetried. I havefound that the heating surface is so effective that itrequires only a short time after closing the valve on the flue 20, tobring the water in the reservoir to a boiling temperature.

Vhile I have described the heater in connection with its use on anincubator, and although I intend to use it chiefly on incubators, I donot desire to relinquish any rights to the heater when used for otherpurposes. It could be made to serve as a heater for the artificiallyheated hot bed, and other uses may develop later, and I wish it to beunderstood that I reserve to myself the right to put the heater to anyuse which it may be found to serve.

Having thus described my invention, What I claim and desire to protectby Letters Patent of the United States is 1. A boiler comprising a pairof sheet metal strips, one of said strips being relatively wide and bentu shape, the other strip being narrow and bent into triangular shape andbeing of a width substantially equal to the space between the sideportions of the first strip and secured therebetween to provide a boilerenclosure between the two .folded and assembled strips.

:2. A boiler comprising a pair of sheet metal strips, one strip beingrelatively wide and the other strip being relatively narrow, the widestrip being U-shape to provide a pair of side walls and a connecting endwall,

the narrow strip being bent around to bring its opposite ends togetherand provide an enclosure therein, said narrow strip being of a widthequal substantially to the spacing apart of said side walls and securedtherebetween to provide a boiler enclosure, said narrow strip beingspaced from the said end wall to provide between the latter and the sidewalls and the narrow strip a flue extending along one edge of theboiler.

8. An incubator boiler consisting of an end wall and spaced side walls,said end and side walls being integral. an integral righttriangledelement secured to said side walls in the space therebetween, one of thelegs of the element being parallel to and spaced from the end wall, theother leg partially closing the space between the upper edges of thespaced side walls, the triangled element and the side walls togetherconstituting a closed water receptacle, the vertical space enclosed bythe side walls, the end wall and the perpendicular leg of the triangledelement therefore a flue for the passage of heated air, and the openspace bounded by the side walls and the hypothenuse of the triangledelement being a by-pass for the passage of the heated air.

In testimony whereof I atlix my signature.

GEORGE E. CHRISTENSEN.

